> Absolutely that would work, but getting them coincident in all degrees=20 > of freedom is not that easy. Yeah, that's what I thought. Endless tinkering with mechanicals probably not worth it. And of course wood isn't the smoothest or colour-consistent material. The pencil lives another day !! Joe --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .